 I have a new computer, which I'm not going to show you because it doesn't work yet. The reason why it doesn't work is because it comes in four different pieces, each of which needs its own 6 volt power supply, which I don't have. Now, in a previous video, I built this, well, bodged together, this epic bench power supply at an old PC power supply. The problem is that while this generates 3.35 and 12 volts, it doesn't generate the 6 volts this thing needs. So what I'm going to do today is fairly crudely and shoddily make a 6 volt power supply for it based around one of these DC to DC converter modules, one of these plastic boxes and lots of these 4mm banana plugs because banana plugs are awesome. This is not going to be particularly complex. Essentially, all I need to do is to stick these in this box, put this inside the box and wire it all up. I also have a little self-powered voltmeter. That would be great to put in the box as well if I can manage it. So most of what I'm going to be doing is drilling holes. So this is not going to be technically complex. Now, these power supply modules are great things. They cost, oh, Frank or two each. They are adjustable. They are reasonably efficient. You can feed them any reasonable DC voltage and outcome any other reasonable DC voltage. And they're really good for this sort of thing. This one's rated at 2 amps, which I frankly don't believe. But we'll see how it goes. I can always upgrade it to a heftier one if needed. Now, the banana plugs are going to be fitted into the box and the actual plugs themselves, of course, go into the box. There's enough clearance. So I can have four sets of pairs in a row on the top for the output. And I also need some inputs as well, which will come from the 12 volt supply of the big power supply. But I need to make sure that they don't actually, you know, touch each other. It looks like there'll be enough space. So if I put these near the edge, then these ones can go in the middle. That should be fine. So let's do some measurements and see how all this goes together. So the box is 70, call it 70 millimetres by... These are 11 millimetres across. So if I place these one centimetre from the edge, put another one out on both sides, that should be fairly robust and will provide... How much space do we have? We can put those together fairly close together. Okay. Well, these have to go in the side. So where did the red ring go? So these can go next to each other, fairly close together, and then these will go in set. Okay. That should work. So the first thing is I need to drill holes for the input on the edge. It's not actually going to be red and black for the input. It's going to be yellow and black to remind me to plug it into the 12 volt supply. That'll do. So first we need to do a pilot's hole. Of course I have nothing like a drill press. So what you're going to see is mostly an unfocused blur of me failing. Put the drill in straight, shall we? Right. So these are going to be my pilot's holes. Let me just double check the positioning again. That looks okay. So we take out the pilot drill. See if this is actually focusing. It'll do. And we use the big drill bit. Yeah, that's actually taking longer than I thought. So let's try something else. I'm just going to just look for another drill bit. Okay, so that one is actually a wood drill bit. So I'm going to try the plastic one instead. Sorry, the HSS one is designed for metal. See if this works better on the plastic. The tips are different shapes. So let's have a go. Oh, yeah. Worked way too well. So it's actually cut most of the way through the hole with just that. So let's go back to this one and clean things up a bit. Because it's got wedged. Let's pick some of this stuff up. Yuck. Anyway, that's done. Okay, it's a bit messy but nothing we can't deal with. Okay, now this was going to be... This was the input. It was going to be black and yellow. And in fact, now I remember, I am using one of these, which is a different model of banana plug to these. So let us just hope that it's still compatible. That seems to be solid. But it's to go in. A sudden horrible thought. Did I buy the wrong size of banana plug sockets? It should be standard. But no, they're not going in. Those ones work, but the yellow one doesn't. I think I may have cocked that up. Is it such a thing as a 3mm banana plug? Oh well. Luckily I have enough of these ones that I can make this work. This will just have to be red instead. I really think I can take these back. Never mind. It'll look neater like this anyway. I just need to remember that the input needs to go into the 12V line. Nothing bad will happen if I plug it into the 5V line and the big power supply. It just won't work. These little DC converters will accept almost anything and omit almost anything, but of course they can only lower the voltage, not raise it. So this is a fairly cheap one that I got at the same place as the others. It's a banana plug I've had for ages. So if it was just one of them, I would put it down to poor tolerances, but there does appear to be a metal ring inside these plugs. So I have a feeling that these are just very badly made, given that they cost like 40 Rp each. I'm not very surprised. Anyway, we have our input and now we want output. Now this is 70 mil cross and we want four sockets in a row. So 70 divided by 5. Now in the other axis we have two rows. So I could do it by bisecting, but of course we need to make sure that the other banana plugs, we need to make sure that when the plugs go in they don't hit these. So in fact the spacing is going to be here. I can do that by measuring the distance here and halving. That goes in there. All right. So now we change drill bits again back to our pilot drill bit, which is here. So now I am going to actually remove these two sockets again and then go off camera and clean the whole thing up with IPA because I want to get the lines off. I want it to look reasonably good when it's done. I mean it's something I'm making so there is a limit as to how good it can be. It looks lovely. Okay, be right back. Well the IPA didn't get it all off, but good enough. So because I'm having trouble with the drilling I'm actually going to try using a rather smaller drill bit this time just to see if that works. I can then go through again with the big one. So let's see how well this actually works shall we? Once I've done all the drilling then I can get on to the bits that I can actually know how to do. More or less. I'm really very happy with this. What I think is going to happen is it's going to get most of the way through and then it's going to jam again and wrench it out of my hand and possibly you know end up slamming against the vice. Yeah let's down scale a bit more shall we? So if I use a really small bit and then work up maybe that will actually work better. Yeah that's better. The early bits are plastic. Okay move up to the... I don't know how big this bit is. The number's rusted off. I've had these bits for a long time. It's better, but not much. That works. Yeah I need a drill press. Wow, okay. Maybe I don't. That's not actually cutting. That's not drilling. It's just sort of cutting its way through. It's producing reasonable holes. Okay you have holes. So that would be the bulk of the drilling. There is actually one more hole that I do want to put in which is for the voltmeter. Ideally I would cut a square hole and mount this thing from the back but I really don't think that my hardware wrangling skills are good enough for that. So I'm just going to put a hole in for the wires and then stick the thing on the outside. So in fact the wires go... It's not going to be precise. I'm not even going to bother. So one more drill hole. I get to start assembling it. So these wires go down here and it will stick on using high tech sticky pads here and tell me what voltage the regulator is set to. Okay. Right, time to put these back on again. So let's start with... So I have a big bag full of banana plug stuff. Now which of course I know that half of them are not working. So let's pull out the ones that do and start assembling. Now I look at the design. I could have... I was intending David, hang on. Ah, I'm an idiot. So I used a small size but didn't go through with the big 9mm drill and make the holes big enough to actually put the banana plugs in. And what I was going to say however is these ones go down flush. You see the plastic here is in two parts and the inner plastic ring goes on the inside. I can actually mount them this way so they sit clear of the rest of the box and then plug doesn't stick as far through. So I wonder whether that might be preferable. It was safe me having to make the holes bigger but no, I think I'll do this one properly. Hopefully this shouldn't be too hard. So 9mm drill, 8. 9. Yeah, that was horrible. I have mentioned I want a drill press, right? Okay, so let's clean that a little bit. Right, so all annoyingly fiddly. I hope the thing works once I'm done with it. I mean there's nothing particularly complicated here. The electronics module is foolproof although I don't know what happens if you connect up the input supply backwards. Which with banana plugs is actually possible though you have to be pretty careless to do so. And I do have a diode as I was thinking of running in line with the input. But it's pretty low rated so I may just not bother with it. Hmm, they could be lined up better. My holes are, yeah, nowhere near each other. Yeah, the whole drilling process with this plastic, just wrenching it around, you're not going to get decently lined up holes doing that. I mean I'm sure you could if you knew what you were doing but I don't. Again, if I had a drill press. So that's most of our box. The plugs, oh dear, that's dreadful. We plug this side into the bench power supply and this side into whatever it is I want to power. So now I need to wire it up at the bottom of the box. Apparently it only has three screws. Four screws. So we'll fasten together like this. This will go in here. So now I need to just wire this up. So if you assume it goes this way, let's put the ground on the bottom. The module has four solder tags in positive, negative, out positive, negative. So we go in here and the wiring should be straightforward. Okay, so what we need for this is a soldering iron, some solder, some wire. So this is stranded wire because it wants to be flexible. I need some water and then we should be ready to start assembling it. All right, the soldering iron is warming up. So let us do some wire. I have this wonderful automatic wire stripper. It's wonderful when it works. It means it's wonderful about four-fifths of the time. I've never been particularly good at stripping wire with wire cutters. I mean, I can do it. I just don't really want to. I also got this terrible little vice for randomly holding stuff, which is what you use vices for, because soldering would be so much easier with more hands. So I can solder the pads. I get the solder onto the pads. I can tin the pads to the wire about here. I want lots of slack because I'm going to be taking the lid off this thing a lot. Okay, this is input positive. So solder it on this end. Tin the tag. And you know what? I'm going to do the black side now. Yeah. So what's happened here is that it's grabbed the wire and has pulled it through the insulation. So I'm actually going to have to cut off the other end. There's some more wire there. So now I'm a rather shorter piece of wire than I was originally hoping. It's going to be good enough. So the black was going to be in the downside. So in fact, that's going to be too short because it is not going to reach as far as I wanted. This is why I stripped the ends before removing it from the reel. There's some more wire. Right. That one worked. This too in negative. Those pads have not tinned at all. The solder is just not sticking to them. It's better if that one is stuck. And that one is stuck. Right. So I think I'll screw this up again. The red wire is not long enough. Nah, it'll do. But I do want to adjust the position of the solder tag a little. Requires this one. So it will go like this. The output side will connect to these here. But these need to be bridged together. So we're doing this next together. We can manage it. So this little piece of black wire will help here. So we tin the ends. It ties this too long. So what I was thinking was to connect the two pads together like this. But we're actually also going to need to solder the patch wires to the module itself. And the little voltmeters. Own wires. Which will be coming through this hole here. Trying to solder multiple things onto the same solder tag. It's always a pain because it's the solder one thing on that comes off. So what do I have here that might be useful? Here is in fact my salvage wire. I've got lots of pieces of little, quite thick, decent wires. These actually came from the power supply project. You've got a little piece of wire. Just the right length is down there. It wants to be just a touch shorter. In fact that has managed to pull some of the wire through the insulation. So never mind. It'll be fine. That's a dreadful joint. Very very dry. Get the tin inside of the wire. I think I did. Yeah that's made contact. That's really not my best work. Yeah that's actually dreadful. So let's try and do something a bit cleverer on this side. These solder tags handy holes in them. So if we line up the holes like so. And get a nice piece of red salvage wire. You see I can put the wire in the hole. And that will hold it mechanically in place. Even if I have to remelt the solder tag. Which I will need to do to put the other bits of wire on. That in here? Yep. Working so well actually. I think my wire is quite long enough. That's solder. Let's tin this solder tag. The reason for using the salvage wire rather than the new stuff. It's the salvage wire is significantly thicker. Not that I expect much more current to this stuff. But yuck. That's dreadful. But it should at least work. Just to give that a try. It'll do. Right. So now I need to connect it up to the power supply module. I do not. Yeah that's long enough. Alright now let's trim that very slightly. So this goes on here. Easy. Okay and now I need the other bit of that wire. And check the side drawer. That is black and red. Which is long enough but the wrong colour. I don't believe I've got any suitably long black to be honest. Yep. Okay. Yeah this has to be the longer side. So no I don't have anything. I just have to use some of the new stuff. Okay. This solders on here. Remember hopefully yuck this all goes. It's going to go like this. So this end solders down onto this pad here. Now this is going to be tricky because there's something already soldered there. This is the one I actually hooked under so it shouldn't be too difficult. So all I need to do is that. The black side likewise needs to go on here. But as soon as I do this this wire will spring up. I did my best to keep the tension low and the wires not actually pushing down onto the solder. So that goes in like this. And in fact I have a suitable sticky pad to fasten it down with. Which I won't do just yet because I want to put the voltmeter on and make sure it works first. Now where did I put the voltmeter? Here it is. Okay. For the voltmeter it's wires go through here. Put them both the same side of the as usual black goes to black. Red goes to red. So these are more manageable lengths. Longer than that shall we? Okay. And that one. Tin. These voltmeter modules are awesome. They are completely self-powered. That is they use the voltage they are measuring to run their own electronics. So you just like hook them up and they work. Below about three volts they all go a bit grey. And below about two and a half they don't work at all. But the stuff I'm doing here they are ideal. That's not melted away through my nice new project box with the soldering guide. Alright. I will use the sticky pad to stick the voltmeter down. Like so. Okay. So let's pull out some banana plugs. Black goes to black. Red goes into yellow on the bench power supply which you can't see but is over here. And that goes into the red banana plug. 24.7 volts. We are actually looking for six. So screwdriver. Adjustment screw. And it all the way down to... There's actually a fair bit of slack in the pot here so. But they seem to be reasonably accurate. So now I need my voltmeter. So you may notice that this... What you are looking at here is slightly different from what you are just looking at. Turns out that my shiny new camera has a hardwired video limit of half an hour. And I just went over a take. So some footage just got lost because I didn't notice it shut down. However you saw enough to see that it all actually worked. I was in the process of hooking it up to the voltmeter to see what the actual voltage was. So I'm just going to recreate that now. I mean I know it works because I've just made it work. But you didn't so. Besides it looks nicer now it's all in the box. So we hook it up. We set that to volts. We turn the power supply on. And this box registers 6.03. And my voltmeter registers 6.05. And I think that's a success. And I've got this nice little gray box. I can wire it up to my various bits of hardware. Although I will need to wire up some plugs. Two banana plugs. I plug it into here and make it all work. And if I ever need to generate different voltages for something else I can just take a lid off this and twiddle the pot. And it will work fine. One interesting thing I want to try. However is, yes camera is in fact still recording. Now currently it's plugged into the 12 volt line. So I unplug that and plug it into the 5 volt line. What does it do? That's actually working. What earth is that generating 6 volts from the 5 volt line? I was really not expecting that. Hang on, I need to try something. So that's actually getting 5 volts from the power supply. And it turns it into 6 volts. It steps up. I did not know that. What about 3 volts? Okay. I just plugged it into the 3 volt line and my power supply turned itself off. I've just wrecked my power supply. Go me. Yeah. Oops. That's awesome. I've probably just blown the fuse in it. Well now I know not to do that. I still have some other power supplies I can run this thing off so I can still get my stuff done. But this is the first time I've actually used my big power supply for something seriously. And I've just tried it. That's awesome. Yeah, I'm going to investigate this offline I think. But yeah, the first thing I need to do is to figure out what's wrong with my big power supply. It was looking like it's gone so well. Good news. My big power supply is fine. It was a self-resetting cutout. Good to know that it has a safety features like this. Good to know that they cut out on demand. Good to know it all actually works. And this is fine. And now I'm going to sign off properly before I break something else. Goodbye.